Cold slurry containment

ABSTRACT

The present invention provides methods and devices for controlling a cold slurry that is delivered to a target tissue and for limiting heat transferring from surrounding tissue to the target tissue. In particular, a balloon structure is deployed at or near a point of delivery to act as a physical and/or thermal barrier. In some instances, the balloon structure can act as a pressure device obstructing the flow of warm blood into a treatment area, which can melt the cold slurry.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. § 119(e) of U.S.Provisional Application Ser. No. 62/482,008 filed on Apr. 5, 2017 theentire disclosure of which is incorporated herein by reference.

BACKGROUND

Cold slurries used in medical applications typically comprise apartially frozen saline solution. Cold slurries are used in surgicalapplications to induce therapeutic hypothermia and slow organ and tissuemetabolic rates thereby protecting a patient's organs during a surgicalprocedure. Cold slurries can also be injected into a patient forselective or non-selective cryotherapy and/or cryolipolysis.

Approaches to preparing and delivering a cold slurry to fat tissuethrough a cannula or needle are disclosed in International ApplicationNo. PCT/US2015/047292; U.S. Patent Application Publication No.2013/0190744; and U.S. Provisional Application No. 62/416,484, which areincorporated herein by reference in their entirety. A cold slurry hashigh fluidity making to possible to inject the cold slurry through asmall cannula or needle. Once the cold slurry is delivered, heattransfers from the target tissue to the cold slurry. This lowers thetemperature of the target tissue, so that cryolipolysis can occur.

Because the cold slurry is highly fluid, it tends to spread out fromwhere it is delivered to surrounding tissue. A three cubic centimetervolume of cold slurry can cover an area that is about the size of asaucer plate. Heat from the surrounding tissues is also transferred tothe cold slurry. Additionally, blood flowing into the treatment area canwarm the cold slurry. As more heat is transferred to the cold slurry,the ability for the cold slurry to lower the tissue temperature of thetarget tissue decreases. Consequently, more cold slurry may be neededfor an effective treatment. Another challenge to delivering a coldslurry is protecting tissue surrounding the target tissue from thecooling effects of the cold slurry.

SUMMARY

The present invention provides methods and devices for controlling acold slurry that is delivered to a target tissue and for limiting heattransferring from surrounding tissue to the target tissue. Inparticular, a balloon structure is deployed at or near a point ofdelivery to act as a physical and/or thermal barrier. In some instances,the balloon can act as a pressure device obstructing the flow of bloodinto a treatment area, which can melt the cold slurry.

A balloon structure for use in the invention can take various forms andshapes, and can have chambers that can be opened or closed to controlthe shape of the balloon. In some examples, balloons are nested withineach other and filled with various fluids or gasses of varyingtemperatures. For example, in one embodiment, a first inner balloon isfilled with a cool mix of water and glycerol, and a second innerballoon, which encloses the first inner balloon, is filled with acoolant gas/fluid (e.g., liquid nitrogen) to freeze or chill the coolmix in the first inner balloon. There can even be a third balloon, whichencloses the second inner balloon. The third balloon is filled with athermal insulator, such as air, to protect surrounding tissue from thecold temperatures of the first and second inner balloons. The multipleballoons can be filled at the same time or at separate times.

A deployment device can be used to deploy the balloon. The device canhave one or more working channels to control the function of the balloonor a collection of balloons. For example, the device has an applicationcannula for deploying multiple balloons one within the other, or onenext to each other. In some examples, multiple balloons can be put touse with a set of deployment devices.

One aspect of the invention includes methods of controlling tissuetemperature. Preferred methods include delivering a cold slurry to atarget tissue located underneath a subject's skin. The target tissue iscooled to a lower tissue temperature as heat is transferred from thetarget tissue to the cold slurry. Methods further include limiting heattransfer from the surrounding tissue to the target tissue, which in turnslows down rising tissue temperature. Heat transfer can be limitedusing, for example, a balloon filled with a thermal insulator, such as afluid, gas or air. The fluid/gas filled balloon acts as a barrier (orblock) between the cold slurry and the surrounding tissue. The fluid/gasfilled balloon can also act as a pressure device that exerts pressureagainst the surrounding tissue. The pressure exerted can constrict ablood vessel in the surrounding tissue and limit warm blood from flowinginto the treatment area.

Another aspect of the invention is a device for carrying out the aboveapproach. Preferred devices include a first cannula for delivering acold slurry to a target tissue underneath a patient's skin, therebycooling the target tissue. The first cannula includes a first opendistal end and a first proximal end in fluid communication with a sourceof cold slurry. Devices further include a second cannula having a secondopen distal end and a second proximal end in fluid communication with asource of a thermal insulator. Devices further include a balloondisposed around the second open distal end of the second cannula. Theballoon is positioned at or near tissue surrounding the target tissue.The balloon has a volume that is filled with the thermal insulator thathas been delivered through second cannula. The filled balloon limitsheat from transferring from the surrounding tissue to the target tissue.

The balloon can have a first chamber facing the target tissue and asecond chamber facing the surrounding tissue. The first chamber is influid communication with the first open distal end and is filled withcold slurry delivered through the first cannula. The second chamber isin fluid communication with the second open distal end and is filledwith the thermal insulator delivered through the second cannula. Thisconfiguration cools the target tissue while projecting the surroundingtissue.

Some devices have two balloons. A first balloon is disposed around thefirst open distal end of the first cannula and positioned at or near thetarget tissue. The first balloon has a volume for receiving the coldslurry delivered through the first cannula. A second balloon is disposedaround the second open distal end of the second cannula. The second hasa volume filled with the thermal insulator. The first balloon containsthe cold slurry within its volume while the second balloon, positionedat or near tissue surrounding the target tissue, limits heat fromtransferring from the surrounding tissue to the target tissue.

Yet another aspect of the invention is a containment device that isapplied over a patient's skin to limit/control the spread of cold slurryand/or its cooling effect from outside the patient's body. Thecontainment device has an opening that defines a containment zone withinwhich the cold slurry and/or its cooling effect is confined. The openingis surrounded by a pressure surface for applying pressure around thecontainment zone. Preferred devices include a pressure surface that is ahollow inside and that can expand when filled with a fluid or gas, suchas air. Force is exerted by pumping air/fluid into the pressure surfacecausing it to expand and press against the patient's skin. The targettissue experiences little or no pressure because of the opening. Thesurrounding tissue, on the other hand, experiences positive pressure.This positive pressure limits the spread of cold slurry and/or itscooling effect from the target tissue to the surrounding tissue.Additionally, the pressure exerted by the containment device canconstrict blood vessels in the surrounding tissue and limit warm bloodfrom flowing into the treatment area.

Some containment devices can have a pressure surface that is dividedinto segments, for example, concentric rings. The segments can befilled, individually, such that the pressure exerted by each segment isdifferent. For example, a first segment closest to the opening is filledso that the pressure exerted against the patient's skin is greater thanthe pressure exerted by a second segment. The difference in pressureapplied by the containment device can help control the migration of coldslurry. Additional, the different pressures exerted by the containmentdevice segments can facilitate tissue contouring.

Still yet another aspect of the invention is a warm fluid removal devicefor removing melted cold slurry from the treatment area. Preferreddevices have a distal end that is positioned a distance away for thetarget tissue and within the surrounding tissue. The devices furtherinclude a proximal end that is coupled to a vacuum pump that providesthe suction to remove the warm fluid from the treatment area. The vacuumpump is operatively coupled to a controller for operating the vacuumpump. The controller can operate the vacuum pump continuously orintermittently. The controller can also monitor the temperature of thetarget tissue using a temperature probe and operate the warm fluidremoval device in response to the rising tissue temperature.

Example warm fluid removal devices can be U-shaped and surround thetarget tissue when in use. These devices have a plurality of holesdefined along their length through which warm fluid is removed from thetreatment area. The warm fluid removal devices can also include an opendistal end to further enhance removing warm fluid from the treatmentarea. These devices can further have a non-operating mode and anoperating mode. In the non-operating mode, the warm fluid removal deviceis substantial linear in shape. In the non-operating mode, the warmfluid removal device can be readily inserted through the patient's skin,advanced to the tissue surrounding the target tissue, and removed fromthe patient when the cold slurry treatment is done. In the operatingmode, the warm fluid removal device is U-shaped with the open end facingthe target tissue. The warm fluid removal device can be mechanicallyactuated between the non-operating mode and operating mode with atension wire, for example. In another example, the warm fluid removaldevice is made for a shape memory alloy, such as nitinol. The warm fluidremoval device can change from the linear shape to the U-shape, and backto the linear shape in response to changes in temperature.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram of an approach to delivering a cold slurry andcontrolling its migration and/or cooling effect.

FIG. 2 is a side view of a balloon acting as a thermal barrierprotecting a nerve from the cooling effect of the cold slurry.

FIG. 3 is a side view of a balloon acting as a pressure device limitingblood flow into a treatment area.

FIG. 4 is a sectional view of a cold slurry delivery device.

FIG. 5 is a view of a cold slurry delivery device for delivering andreplenishing cold slurry.

FIG. 6 is a sectional view of a two-chamber balloon for delivering coldslurry to a target tissue and protecting an adjacent tissue from thecooling effect of the cold slurry.

FIG. 7 is a view of an example balloon having projecting arms.

FIG. 8 is a view of an example balloon having multiple compartments.

FIG. 9 is a view of an example cold slurry temperature monitor.

FIG. 10 is a view of an example cold slurry temperature monitor withmultiple temperature sensors.

FIGS. 11A and 11B are views of example containment devices forcontrolling cold slurry and/or its cooling effect from outside thepatient's body.

FIGS. 12A and 12B are views of example warm fluid removal devices forremoving melted cold slurry from a treatment area.

FIGS. 13A-13C are views of an example guide for deploying a cold slurrycontainment device.

FIGS. 14A and 14B show a fenestrated cannula with balloons in retractedand expanded states.

FIG. 15 shows various opening designs for a fenestrated cannula and theresulting shapes of balloons expanded therethrough with slurry.

DETAILED DESCRIPTION

FIG. 1 shows a cold slurry being injected into a patient. A cold slurrydelivery device 100 having a cannula is inserted through the patient'sskin and advanced to a location at or near a target tissue 105 (shown inphantom line). A cold slurry 110 is then delivered. Heat from the targettissue 105 is transferred to the cold slurry 110, which in turn lowersthe temperature of the target tissue 105. After delivery, an areaaffected by the cold slurry 110 expands to a size larger than theinitial delivery site (shown in the figure as arrows radiating outwardlyfrom the delivered cold slurry 110 and dashed circles of increasingsize).

FIG. 1 further shows an approach for controlling the cooling effect ofthe cold slurry 110. A deployment device 115 having an applicationcannula 120 is inserted through the patient's skin. At the distal end ofthe application cannula 120, there is a controlling end 125. Thedeployment device 115 is advanced until the controlling end 125 is at alocation between the target tissue 105 and an adjacent (surrounding)tissue 135. The controlling end 125 includes a balloon 130. While theballoon 130 is shown having a linear shape, it can have any shape, suchas a ring that encircles the target tissue 105. The balloon 130 isfilled with air to create a barrier between the adjacent tissue 135 andthe spreading cold slurry 110. The balloon 130 limits heat transferringfrom the adjacent tissue 135 to the cold slurry 110.

The approach provides several benefits. By acting as a temperaturebarrier, the balloon 130 can slow down the melting process, therebyprolonging the usefulness of the cold slurry 110. The balloon 130 canfurther help keep the target tissue 105 cold and thus, increase theeffectiveness of the cold slurry treatment. By acting as a temperaturebarrier, the balloon 130 also protects the adjacent tissue 135 frombeing adversely affected or damaged by the cold. For example, FIG. 2shows the balloon 130 placed between the cold slurry 110 and a nerve140. The balloon 130 limits the cooling effect of the cold slurry 110 onthe nerve 140. Beneficially, this lowers the possibility of damaging thenerve 140.

FIG. 3 shows another application of the balloon 130. The balloon 130filled with air or fluid is placed next to a blood vessel 150. Theballoon 130 exerts pressure on the blood vessel 150 causing it toconstrict and limit blood flow 155, as shown. By reducing the amount ofwarm blood flowing into a treatment area, the balloon 130 can slow downthe melting process, thereby prolonging the usefulness of cold slurry.The balloon 130 can further help keep a target tissue cold and thus,increase the effectiveness of the cold slurry treatment.

FIG. 4 shows an example cold slurry delivery device 200. The device 200includes an application cannula 205 that is open at its distal end anddefines an outlet 210. A controlling end 215 includes an outer balloon220 disposed around the outlet 210. The application cannula 205 is influid communication with the interior volume of the outer balloon 220.The application cannula 205 includes a fluid delivery cannula 225. Theapplication cannula 205 and the fluid delivery cannula 225 share acommon longitudinal axis and can be said to be coaxial aligned.

The fluid delivery cannula 225 is open at its distal end defining afluid outlet 230. The controlling end 215 further includes an innerballoon 235 disposed around the fluid outlet 230. The fluid deliverycannula 225 is in fluid communication with an interior volume of theinner balloon 235, which is labeled 240 in the figure. The inner balloon235 is located inside the outer balloon 220. As shown, the inner balloon235 occupies a portion of the interior volume of the outer balloon 220leaving a space or gap 245 between an outer wall of the inner balloon235 (which is labeled 250 in the figure) and an inner wall of the outerballoon 220 (which is labeled 255 in the figure).

To use the cold slurry delivery device 200, the application cannula 205is inserted through the patient's skin and the controlling end 215 isadvanced to a location at or near a target tissue in much the samemanner as described above with reference to FIG. 1 . In this example,the outer balloon 220 and the inner balloon 235 are inserted into thepatient's body in their uninflated state. The outer balloon 220 isfilled with air that is supplied through the application cannula 205.The inner balloon 235 is filled with a cold slurry 260 that is suppliedthrough the fluid delivery cannula 225. The air filling the gap 645between the inner balloon 235 and the outer balloon 220 acts aninsulator and protects the surrounding tissue from damage. The innerballoon 235 can also be filled with a fluid, gel, inorganic aerogel,foam or other thermal insulator.

FIG. 5 shows another example of the cold slurry delivery device 200 fordelivering a cold slurry. This example is similar to the one describedabove with reference to FIG. 4 with the addition of a fluid returncannula 265. The fluid return cannula 265 is housed within theapplication cannula 205 together with the fluid delivery cannula 225, asshown. The fluid return cannula 265 removes cold slurry from the innerballoon 235 that is no longer at the desired temperature. Replenishingthe “old” cold slurry with “fresh” cold slurry in this manner canaccommodate for the eventually melting of cold slurry. This approach isparticular useful for a treatment that requires a long period ofcooling.

FIG. 6 shows an example balloon 300 for delivering cold slurry. Theballoon 300 has a first chamber 305 and a second chamber 310, as shown.The first chamber 305 is filled a cold slurry (or other cooling fluid)and faces a target tissue 315. The second chamber 310 is filled with air(or other gas) and faces an adjacent tissue 320, which is near thetarget tissue 315. This configuration allows the balloon 300 to cool thetarget tissue 315 while protecting the adjacent tissue 320 from thecooling effect of the cold slurry.

Examples of the balloon can have any shape in addition to the linear andspherical examples described above with reference to FIGS. 1-5 . Forexample, FIG. 2 shows the balloon 130 having a length (L) greater thanits width (W) and having a concave shape. The point of concavity isdefined by a point along an axis offset and parallel to a longitudinalaxis 165. As another example, FIG. 7 shows a balloon 350 with severalprojecting arms or balusters 355.

Other examples of the balloon can have a number of chambers that can beopened or closed to control the shape of the balloon. For example, FIG.8 shows a balloon 400 with four compartments 405 a-405 d (generally405). The compartments 405 can be filled with various fluids or gassesof varying temperatures. The balloon 400 has a length (L) greater thanits width (W).

FIG. 9 shows a cold slurry temperature monitor 500 for measuring thetemperature of the cold slurry. The cold slurry temperature monitor 500can be a standalone device or incorporated with the cold slurry deliverydevice 100, 200 (of FIGS. 1 and 5 ) or the deployment device 115 (ofFIG. 1 ). As shown, for example, the cold slurry temperature monitor 500extends from an application cannula 505 (e.g., the cannula of the coldslurry delivery device 100). The cold slurry temperature monitor 500 canmove between an extended position, which is shown in the figure, and aretracted position. In the retracted position, the cold slurrytemperature monitor 500 is shielded within the application cannula 505.This helps with inserting the cold slurry temperature monitor 500through the patient's skin and advancing the monitor 500 to a locationat or near the cold slurry.

In the example shown, the cold slurry temperature monitor 500 includesat a temperature sensor 510 at its distal tip. Without limiting theprinciples of the invention, the temperature sensor 510 can be a forwardinfrared (FIR) sensor. As shown, the cold slurry temperature monitor 500can be moved to intermediate positions between the retracted andextended positions. These intermediate positions together with theextended position correspond to different locations within the coldslurry, which are labelled in figure “A” through “E”. By moving the coldslurry temperature monitor 500 to the intermediate positions and theextended position, a temperature gradient (or “temperature thru depth”)of the cold slurry can be determined. The temperature gradient, in turncan, can be used to assess, for example, the capacity (capability) forthe cold slurry to cool the target tissue.

FIG. 10 shows another example of the cold slurry temperature monitor 500having multiple sensors 515 a-e (generally 515) spaced along the lengthof the monitor 500. Each of the sensors 515 measures a differentlocation within the cold slurry. For example, sensor 515 c measures thetemperature of the cold slurry at the location labelled “C” in FIG. 9.In this way, a temperature gradient of the cold slurry can be determinedwithout having to move the cold slurry temperature monitor 500.

FIG. 11A shows the cold slurry delivery device 100 of FIG. 1 deliveringa cold slurry to the target tissue 105 underneath the patient's skin(which is shown in phantom line). A containment device 600 is appliedover the patient's skin to control the spread of the cold slurry and/orits cooling effect from outside the patient's body. The containmentdevice 600 has an opening 605 that defines a containment zone 610 withinwhich the cold slurry and/or its cooling effect is substantiallyconfined. The opening 605 is surrounded by a pressure surface 615 forapplying pressure around the containment zone 610. As shown, thecontainment device 600 is applied with the opening 605 placed over thetarget tissue 105 and the pressure surface 615 over the surroundingtissue 135 (which is shown in phantom line).

In a convenient example of the containment device 600, the pressuresurface 615 is a hollow inside and can expand when filled a fluid orgas, such as air. Force is exerted by pumping air/fluid into thepressure surface 615 causing it to expand and press against thepatient's skin. The target tissue 105 experiences little or no pressurebecause of the opening 605. The surrounding tissue 135, on the otherhand, experiences positive pressure. This positive pressure limits thespread of cold slurry and/or its cooling effect from the target tissue105 to the surrounding tissue 135. Additionally, the pressure exertedcan constrict blood vessels in the surrounding tissue 135 and limit warmblood from flowing into the treatment area.

The exerted pressure can be reduced or removed by pumping air/fluid outof the pressure surface 615 causing it to deflate. In a convenientexample, the pumping of air/fluid into and out of the pressure surface615 is done automatically. For example, air/fluid is pumped into thepressure surface 615, such that the containment device 600 appliespressure at or near the start of a cold slurry treatment. After apre-determined amount of time, the air/fluid is pumped out of thepressure surface 615 relieving pressure from the containment device 600at or near the end of the cold slurry treatment.

Shown in FIG. 11B, the pressure surface can be divided into segments 620(shown as a first segment 620 a and a second segment 620 b). Thesegments 620 can be, for example, concentric rings. The segments 620 canbe filled, individually, such that the pressure exerted pressure by eachsegment is different. For example, the first segment 620 a closest tothe opening 605 is filled so that the pressure exerted against thepatient's skin is greater that the pressure exerted by the secondsegment 620 b. The difference in pressure applied by the containmentdevice 600 can help control the migration of cold slurry. Additional,the different pressures can facilitate tissue contouring.

In another example of the containment device, the pressure surface issolid. When a force is exerted against the containment device, thetarget tissue experiences little or no pressure because of the opening.The surrounding tissue, on the other hand, experiences positivepressure. This positive pressure limits the spread of cold slurry and/orits cooling effect from the target tissue to the surrounding tissue.Additionally, the pressure exerted can constrict blood vessels in thesurrounding tissue and limit warm blood from flowing into the treatmentarea.

The solid pressure surface can be divided into segments, for example,concentric rings. The segments can be added or removed to make the sizeof the opening and, in turn, the containment zone bigger or smaller. Thesegments can also be added or removed to make the size of the pressuresurface bigger or smaller and thus change the area over which pressureis applied.

In the examples shown, the containment device 600 has a circular shapewith the opening 605 centrally located and the pressure surface 615concentric with the opening 605. Further, the pressure surface 615 is asubstantially planer surface, as shown. The containment device 600 canbe of any shape suitable for applying pressure to a part of thepatient's body. For example, the containment device 600 can berectangular, triangular or other regular shape. The containment device600 can also have an irregular shape that is adapted to conform to apart of the patient's body being treated. For the example, thecontainment device 600 can be concaved to saddle, for example, thepatient's stomach. The concavity of the containment device 600 isdefined in the context of the device in use.

As shown, the opening 605 and pressure surface 615 are axially aligned,i.e., sharing a common axis. In other examples, the axis of the opening605 and axis of the pressure surface 615 are offset a distance. Thisnon-axial example of the containment device 600 can be useful inapplications where it is desirable to bias the containment of coldslurry more or less to one side of the target tissue 105.

The containment device 600 can be made out plastic, polymer, rubber orother material suitable for applying pressure to a part of the patient'sbody. The containment device can be used manually, for example, aclinician presses (e.g., by way of a handle on the containment device)the device 600 against the patient's skin. Use of the containment device600 can also be facilitated with straps or clamps for wrapping thecontainment device 600 around a part of the patient's body.

FIG. 12A shows the cold slurry delivery device 100 of FIG. 1 deliveringa cold slurry to the target tissue 105 underneath the patient's skin.Heat from the target tissue 105 is transferred to the cold slurry 110,which in turn lowers the temperature of the target tissue 105 to a firsttemperature T1. After delivery, the cold slurry 110 spreads out andaffects an area larger than the initial delivery site (shown in thefigure as arrows radiating outwardly from the delivered cold slurry 110and dashed circles of increasing size). As the cold slurry 110 spreadsout, it melts and lowers the temperature of the surrounding tissue 135to a second temperature T2, which is warmer than the first temperatureT1.

A warm fluid removal device 700 removes the resulting warm fluid fromthe treatment area. The warm fluid removal device 700 has a distal end705 that is positioned a distance away for the target tissue 105 andwithin the surrounding tissue 135. The warm fluid removal device 700further includes a proximal end 710 that is coupled to a vacuum pump715. The vacuum pump 715 provides the suction to remove the warm fluidfrom the treatment area.

The vacuum pump 715 is operatively coupled to a controller 720 foroperating the vacuum pump 715. The controller 720 can operate the vacuumpump 715 continuously such that warm fluid is constantly removed. Thecontroller 720 can operate the vacuum pump 715 intermittently such thatwarm fluid is drawn off at pre-determined intervals. In a convenientexample, the controller 720 monitors the temperature of the targettissue 105 using a temperature probe (e.g., one similar to the coldslurry temperature monitor 500 described above with reference to FIGS. 9and 10 ). When the temperature of the target tissue 105 rises above thefirst temperature T1, the controller 720 responds by operating thevacuum pump 715 and removing the warm fluid from the treatment area.

FIG. 12B shows another example warm fluid removal device 750 forremoving warm fluid from a treatment area. Generally, the warm fluidremoval device 750 has a hoop-like shape. As shown, the warm fluidremoval device 750 is U-shaped with an open end 755 facing the targettissue 105. The warm fluid removal device 750 further has a plurality ofholes 760 defined along its length through which warm fluid is removedfrom the treatment area (shown as arrows). The warm fluid removal device750 can include an open distal end 765 to further enhance removal of thewarm fluid from the treatment area.

In a convenient example, the warm fluid removal device 750 has anon-operating mode and an operating mode. In the non-operating mode, thewarm fluid removal device 750 is substantial linear in shape. In thenon-operating mode, the warm fluid removal device 750 can be readilyinserted through the patient's skin, advanced to the tissue surroundingthe target tissue, and removed from the patient.

In the operating mode, the warm fluid removal device 750 is U-shapedwith the open end 755 facing the target tissue 105 as shown in FIG. 12B.The warm fluid removal device 700 can be mechanically actuated betweenthe non-operating mode and operating mode with a tension wire, forexample. In another example, the warm fluid removal device 750 is madefor a shape memory alloy, such as nitinol.

The warm fluid removal device 750 further includes a proximal end 770that is coupled to a vacuum pump 775. The vacuum pump 775 provides thesuction to remove the warm fluid of the treatment area. The controller781 can operate the vacuum pump 775 continuously such that warm fluid isconstantly removed. The controller 720 can operate the vacuum pump 775intermittently such that warm fluid is drawn off at pre-determinedintervals. In a convenient example, the controller 780 monitors thetemperature of the target tissue 105 using a temperature probe (e.g.,one similar to the cold slurry temperature monitor 500 described abovewith reference to FIGS. 9 and 10 ). When the temperature of the targettissue 105 rises above the first temperature T1, the controller 780operates the vacuum pump 775 to remove the warm fluid from the treatmentarea.

The warm fluid removal device 700 of FIG. 12A (or 650 of FIG. 12B) andthe cold slurry delivery device 100 of FIG. 1 can be operated together,for example, using the controller 720, to replenish “old” cold slurrywith “fresh” cold slurry. Replenishing cold slurry can occurintermittently such that warm fluid is drawn off and cold slurry isdelivered at pre-determined intervals.

In a convenient example, the controller 720 monitors the temperature ofthe target tissue 105 using a temperature probe (e.g., one similar tothe cold slurry temperature monitor 500 described above with referenceto FIGS. 9 and 10 ). When the temperature of the target tissue 105 risesabove the first temperature T1, the controller 720 responds by operatingthe warm fluid removal device 700 to remove warm fluid from thetreatment area; and by operating the cold slurry delivery device 105 todeliver cold slurry to the target tissue 105. This configuration isparticular useful for cooling tissue for an extended period of time.

In a convenient example, any one of the devices described above can bedeployed using a guide. FIGS. 13A-13C show an example of the guide 800to use with the deployment device 115 of FIG. 1 . The guide 800 includesa working channel 805 for housing the application cannula 120 and theballoon 130. The working channel 800 is inserted through the patient'sskin and advanced towards the treatment area. At the treatment area, thedeployment device 115 is pushed out of the working channel, as shown inFIG. 13B. The balloon 130 is then be inflated with a fluid or a gas,such as air, as shown in FIG. 13C, and used to control the cold slurryand/or its cooling effects, as described above. When the treatment isdone, the balloon 130 is deflated and pulled back into the workingchannel 805. The guide 800 is then withdrawn from the patient's body.The guide 800 can have one or more working channels to control thefunction of the balloon or a collection of balloons.

In various embodiments, fenestrated needles or cannulas are providedwith one or more mini or micro balloons that, when filled with atherapeutic cold fluid or slurry, drastically increase surface areathrough which the cannula can transfer heat from surrounding tissue. Theballoons may be modeled after intestinal villi for example and may bedeployed from a single needle or cannula as shown in FIGS. 14A and 14Bor through an array of needles or cannulas. The expansion and retractionof the balloons can be dependent on a differential in wall pressure whenslurry or cold solution flows through the cannula or needle.

An exemplary fenestrated needle or cannula is shown in FIGS. 14A and14B. The fenestrated cannula 1401 may be constructed of a relativelyrigid or inflexible material compared to the balloon 1407 material.Balloons 1407 formed of a relatively flexible or expansible material arepresent in a series of openings 1403 in the rigid cannula 1401. Thecannula 1401 may have a solid tip to allow pressure to build within alumen 1405 of the cannula as slurry or fluid is added. As fluid orslurry is added and pressure within the lumen 1405 builds, therelatively flexible balloons 1407 expand outwardly through the openings1403 as shown in FIG. 14B. The resulting expanded balloons, filled withcold slurry, drastically increase the surface area for thermalinteraction with surrounding tissue. Once fluid or slurry flow ceases,the expanded balloons 1407 retract back within the openings 1403 asshown in FIG. 14A, allowing for ease of insertion and removal of thecannula.

The micro or mini balloons of fenestrated cannulas may be a variety ofdifferent shapes as shown in FIG. 15 . The left column of FIG. 15illustrates the shape of various openings in fenestrated cannulaembodiments of the invention and the right column shows a correspondingballoon shape one a balloon is expanded through an opening of the shapeshown in the left column. For example, a rigid material such as that ofthe cannula itself may be used to divide the opening as shown in FIG. 15. By dividing the opening in two or in quarters, a balloon expandingtherethrough will form two or four separate expanded members. In certainembodiments, the flexibility of the balloon material within an openingmay be varied as shown in FIG. 15 to cause the expanded balloon to takeon different shapes. For example, concentric rings of varyingflexibility may result in an oblong expanded balloon which may beadvantageous for certain treatments.

1-20. (canceled)
 21. A device for controlling tissue temperature, thedevice comprising: a fenestrated cannula for delivering a cold slurrydirectly to a target tissue underneath a patient's skin, therebydirectly contacting and cooling the target tissue, the cannulacomprising a plurality of openings at a distal end and a proximal end influid communication with a source of cold slurry; and a plurality ofballoons, each disposed in one of the plurality of openings andconfigured to expand when exposed to cold slurry from the source of coldslurry and thereby provide an increase in surface area for thermaltransfer from the target tissue to the cold slurry at the distal end ofthe cannula.
 22. The device of claim 21, wherein one or more of theplurality of openings is configured to impart a shape the plurality ofballoons disposed therein when expanded.
 23. The device of claim 22,wherein the shape comprises a plurality of expanded members.
 24. Thedevice of claim 22, wherein the shape comprises an ovoid.
 25. The deviceof claim 22, wherein the shape comprises a sphere.
 26. The device ofclaim 22, wherein one or more of the plurality of balloons comprise twoor more areas of differing elasticity.
 27. The device of claim 21,comprising an array of fenestrated cannulas.